xref: /linux/Makefile (revision b5ec6fd286dfa466f64cb0e56ed768092d0342ae)
1# SPDX-License-Identifier: GPL-2.0
2VERSION = 6
3PATCHLEVEL = 4
4SUBLEVEL = 0
5EXTRAVERSION =
6NAME = Hurr durr I'ma ninja sloth
7
8# *DOCUMENTATION*
9# To see a list of typical targets execute "make help"
10# More info can be located in ./README
11# Comments in this file are targeted only to the developer, do not
12# expect to learn how to build the kernel reading this file.
13
14ifeq ($(filter undefine,$(.FEATURES)),)
15$(error GNU Make >= 3.82 is required. Your Make version is $(MAKE_VERSION))
16endif
17
18$(if $(filter __%, $(MAKECMDGOALS)), \
19	$(error targets prefixed with '__' are only for internal use))
20
21# That's our default target when none is given on the command line
22PHONY := __all
23__all:
24
25# We are using a recursive build, so we need to do a little thinking
26# to get the ordering right.
27#
28# Most importantly: sub-Makefiles should only ever modify files in
29# their own directory. If in some directory we have a dependency on
30# a file in another dir (which doesn't happen often, but it's often
31# unavoidable when linking the built-in.a targets which finally
32# turn into vmlinux), we will call a sub make in that other dir, and
33# after that we are sure that everything which is in that other dir
34# is now up to date.
35#
36# The only cases where we need to modify files which have global
37# effects are thus separated out and done before the recursive
38# descending is started. They are now explicitly listed as the
39# prepare rule.
40
41ifneq ($(sub_make_done),1)
42
43# Do not use make's built-in rules and variables
44# (this increases performance and avoids hard-to-debug behaviour)
45MAKEFLAGS += -rR
46
47# Avoid funny character set dependencies
48unexport LC_ALL
49LC_COLLATE=C
50LC_NUMERIC=C
51export LC_COLLATE LC_NUMERIC
52
53# Avoid interference with shell env settings
54unexport GREP_OPTIONS
55
56# Beautify output
57# ---------------------------------------------------------------------------
58#
59# Most of build commands in Kbuild start with "cmd_". You can optionally define
60# "quiet_cmd_*". If defined, the short log is printed. Otherwise, no log from
61# that command is printed by default.
62#
63# e.g.)
64#    quiet_cmd_depmod = DEPMOD  $(MODLIB)
65#          cmd_depmod = $(srctree)/scripts/depmod.sh $(DEPMOD) $(KERNELRELEASE)
66#
67# A simple variant is to prefix commands with $(Q) - that's useful
68# for commands that shall be hidden in non-verbose mode.
69#
70#    $(Q)$(MAKE) $(build)=scripts/basic
71#
72# If KBUILD_VERBOSE contains 1, the whole command is echoed.
73# If KBUILD_VERBOSE contains 2, the reason for rebuilding is printed.
74#
75# To put more focus on warnings, be less verbose as default
76# Use 'make V=1' to see the full commands
77
78ifeq ("$(origin V)", "command line")
79  KBUILD_VERBOSE = $(V)
80endif
81
82quiet = quiet_
83Q = @
84
85ifneq ($(findstring 1, $(KBUILD_VERBOSE)),)
86  quiet =
87  Q =
88endif
89
90# If the user is running make -s (silent mode), suppress echoing of
91# commands
92# make-4.0 (and later) keep single letter options in the 1st word of MAKEFLAGS.
93
94ifeq ($(filter 3.%,$(MAKE_VERSION)),)
95short-opts := $(firstword -$(MAKEFLAGS))
96else
97short-opts := $(filter-out --%,$(MAKEFLAGS))
98endif
99
100ifneq ($(findstring s,$(short-opts)),)
101quiet=silent_
102override KBUILD_VERBOSE :=
103endif
104
105export quiet Q KBUILD_VERBOSE
106
107# Call a source code checker (by default, "sparse") as part of the
108# C compilation.
109#
110# Use 'make C=1' to enable checking of only re-compiled files.
111# Use 'make C=2' to enable checking of *all* source files, regardless
112# of whether they are re-compiled or not.
113#
114# See the file "Documentation/dev-tools/sparse.rst" for more details,
115# including where to get the "sparse" utility.
116
117ifeq ("$(origin C)", "command line")
118  KBUILD_CHECKSRC = $(C)
119endif
120ifndef KBUILD_CHECKSRC
121  KBUILD_CHECKSRC = 0
122endif
123
124export KBUILD_CHECKSRC
125
126# Enable "clippy" (a linter) as part of the Rust compilation.
127#
128# Use 'make CLIPPY=1' to enable it.
129ifeq ("$(origin CLIPPY)", "command line")
130  KBUILD_CLIPPY := $(CLIPPY)
131endif
132
133export KBUILD_CLIPPY
134
135# Use make M=dir or set the environment variable KBUILD_EXTMOD to specify the
136# directory of external module to build. Setting M= takes precedence.
137ifeq ("$(origin M)", "command line")
138  KBUILD_EXTMOD := $(M)
139endif
140
141$(if $(word 2, $(KBUILD_EXTMOD)), \
142	$(error building multiple external modules is not supported))
143
144$(foreach x, % :, $(if $(findstring $x, $(KBUILD_EXTMOD)), \
145	$(error module directory path cannot contain '$x')))
146
147# Remove trailing slashes
148ifneq ($(filter %/, $(KBUILD_EXTMOD)),)
149KBUILD_EXTMOD := $(shell dirname $(KBUILD_EXTMOD).)
150endif
151
152export KBUILD_EXTMOD
153
154# Kbuild will save output files in the current working directory.
155# This does not need to match to the root of the kernel source tree.
156#
157# For example, you can do this:
158#
159#  cd /dir/to/store/output/files; make -f /dir/to/kernel/source/Makefile
160#
161# If you want to save output files in a different location, there are
162# two syntaxes to specify it.
163#
164# 1) O=
165# Use "make O=dir/to/store/output/files/"
166#
167# 2) Set KBUILD_OUTPUT
168# Set the environment variable KBUILD_OUTPUT to point to the output directory.
169# export KBUILD_OUTPUT=dir/to/store/output/files/; make
170#
171# The O= assignment takes precedence over the KBUILD_OUTPUT environment
172# variable.
173
174# Do we want to change the working directory?
175ifeq ("$(origin O)", "command line")
176  KBUILD_OUTPUT := $(O)
177endif
178
179ifneq ($(KBUILD_OUTPUT),)
180# Make's built-in functions such as $(abspath ...), $(realpath ...) cannot
181# expand a shell special character '~'. We use a somewhat tedious way here.
182abs_objtree := $(shell mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) && pwd)
183$(if $(abs_objtree),, \
184     $(error failed to create output directory "$(KBUILD_OUTPUT)"))
185
186# $(realpath ...) resolves symlinks
187abs_objtree := $(realpath $(abs_objtree))
188else
189abs_objtree := $(CURDIR)
190endif # ifneq ($(KBUILD_OUTPUT),)
191
192ifeq ($(abs_objtree),$(CURDIR))
193# Suppress "Entering directory ..." unless we are changing the work directory.
194MAKEFLAGS += --no-print-directory
195else
196need-sub-make := 1
197endif
198
199this-makefile := $(lastword $(MAKEFILE_LIST))
200abs_srctree := $(realpath $(dir $(this-makefile)))
201
202ifneq ($(words $(subst :, ,$(abs_srctree))), 1)
203$(error source directory cannot contain spaces or colons)
204endif
205
206ifneq ($(filter 3.%,$(MAKE_VERSION)),)
207# 'MAKEFLAGS += -rR' does not immediately become effective for GNU Make 3.x
208# We need to invoke sub-make to avoid implicit rules in the top Makefile.
209need-sub-make := 1
210# Cancel implicit rules for this Makefile.
211$(this-makefile): ;
212endif
213
214export abs_srctree abs_objtree
215export sub_make_done := 1
216
217ifeq ($(need-sub-make),1)
218
219PHONY += $(MAKECMDGOALS) __sub-make
220
221$(filter-out $(this-makefile), $(MAKECMDGOALS)) __all: __sub-make
222	@:
223
224# Invoke a second make in the output directory, passing relevant variables
225__sub-make:
226	$(Q)$(MAKE) -C $(abs_objtree) -f $(abs_srctree)/Makefile $(MAKECMDGOALS)
227
228endif # need-sub-make
229endif # sub_make_done
230
231# We process the rest of the Makefile if this is the final invocation of make
232ifeq ($(need-sub-make),)
233
234# Do not print "Entering directory ...",
235# but we want to display it when entering to the output directory
236# so that IDEs/editors are able to understand relative filenames.
237MAKEFLAGS += --no-print-directory
238
239ifeq ($(abs_srctree),$(abs_objtree))
240        # building in the source tree
241        srctree := .
242	building_out_of_srctree :=
243else
244        ifeq ($(abs_srctree)/,$(dir $(abs_objtree)))
245                # building in a subdirectory of the source tree
246                srctree := ..
247        else
248                srctree := $(abs_srctree)
249        endif
250	building_out_of_srctree := 1
251endif
252
253ifneq ($(KBUILD_ABS_SRCTREE),)
254srctree := $(abs_srctree)
255endif
256
257objtree		:= .
258VPATH		:= $(srctree)
259
260export building_out_of_srctree srctree objtree VPATH
261
262# To make sure we do not include .config for any of the *config targets
263# catch them early, and hand them over to scripts/kconfig/Makefile
264# It is allowed to specify more targets when calling make, including
265# mixing *config targets and build targets.
266# For example 'make oldconfig all'.
267# Detect when mixed targets is specified, and make a second invocation
268# of make so .config is not included in this case either (for *config).
269
270version_h := include/generated/uapi/linux/version.h
271
272clean-targets := %clean mrproper cleandocs
273no-dot-config-targets := $(clean-targets) \
274			 cscope gtags TAGS tags help% %docs check% coccicheck \
275			 $(version_h) headers headers_% archheaders archscripts \
276			 %asm-generic kernelversion %src-pkg dt_binding_check \
277			 outputmakefile rustavailable rustfmt rustfmtcheck
278# Installation targets should not require compiler. Unfortunately, vdso_install
279# is an exception where build artifacts may be updated. This must be fixed.
280no-compiler-targets := $(no-dot-config-targets) install dtbs_install \
281			headers_install modules_install kernelrelease image_name
282no-sync-config-targets := $(no-dot-config-targets) %install kernelrelease \
283			  image_name
284single-targets := %.a %.i %.ko %.lds %.ll %.lst %.mod %.o %.rsi %.s %.symtypes %/
285
286config-build	:=
287mixed-build	:=
288need-config	:= 1
289need-compiler	:= 1
290may-sync-config	:= 1
291single-build	:=
292
293ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
294	ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
295		need-config :=
296	endif
297endif
298
299ifneq ($(filter $(no-compiler-targets), $(MAKECMDGOALS)),)
300	ifeq ($(filter-out $(no-compiler-targets), $(MAKECMDGOALS)),)
301		need-compiler :=
302	endif
303endif
304
305ifneq ($(filter $(no-sync-config-targets), $(MAKECMDGOALS)),)
306	ifeq ($(filter-out $(no-sync-config-targets), $(MAKECMDGOALS)),)
307		may-sync-config :=
308	endif
309endif
310
311ifneq ($(KBUILD_EXTMOD),)
312	may-sync-config :=
313endif
314
315ifeq ($(KBUILD_EXTMOD),)
316        ifneq ($(filter %config,$(MAKECMDGOALS)),)
317		config-build := 1
318                ifneq ($(words $(MAKECMDGOALS)),1)
319			mixed-build := 1
320                endif
321        endif
322endif
323
324# We cannot build single targets and the others at the same time
325ifneq ($(filter $(single-targets), $(MAKECMDGOALS)),)
326	single-build := 1
327	ifneq ($(filter-out $(single-targets), $(MAKECMDGOALS)),)
328		mixed-build := 1
329	endif
330endif
331
332# For "make -j clean all", "make -j mrproper defconfig all", etc.
333ifneq ($(filter $(clean-targets),$(MAKECMDGOALS)),)
334        ifneq ($(filter-out $(clean-targets),$(MAKECMDGOALS)),)
335		mixed-build := 1
336        endif
337endif
338
339# install and modules_install need also be processed one by one
340ifneq ($(filter install,$(MAKECMDGOALS)),)
341        ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
342		mixed-build := 1
343        endif
344endif
345
346ifdef mixed-build
347# ===========================================================================
348# We're called with mixed targets (*config and build targets).
349# Handle them one by one.
350
351PHONY += $(MAKECMDGOALS) __build_one_by_one
352
353$(MAKECMDGOALS): __build_one_by_one
354	@:
355
356__build_one_by_one:
357	$(Q)set -e; \
358	for i in $(MAKECMDGOALS); do \
359		$(MAKE) -f $(srctree)/Makefile $$i; \
360	done
361
362else # !mixed-build
363
364include $(srctree)/scripts/Kbuild.include
365
366# Read KERNELRELEASE from include/config/kernel.release (if it exists)
367KERNELRELEASE = $(call read-file, include/config/kernel.release)
368KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
369export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
370
371include $(srctree)/scripts/subarch.include
372
373# Cross compiling and selecting different set of gcc/bin-utils
374# ---------------------------------------------------------------------------
375#
376# When performing cross compilation for other architectures ARCH shall be set
377# to the target architecture. (See arch/* for the possibilities).
378# ARCH can be set during invocation of make:
379# make ARCH=ia64
380# Another way is to have ARCH set in the environment.
381# The default ARCH is the host where make is executed.
382
383# CROSS_COMPILE specify the prefix used for all executables used
384# during compilation. Only gcc and related bin-utils executables
385# are prefixed with $(CROSS_COMPILE).
386# CROSS_COMPILE can be set on the command line
387# make CROSS_COMPILE=ia64-linux-
388# Alternatively CROSS_COMPILE can be set in the environment.
389# Default value for CROSS_COMPILE is not to prefix executables
390# Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
391ARCH		?= $(SUBARCH)
392
393# Architecture as present in compile.h
394UTS_MACHINE 	:= $(ARCH)
395SRCARCH 	:= $(ARCH)
396
397# Additional ARCH settings for x86
398ifeq ($(ARCH),i386)
399        SRCARCH := x86
400endif
401ifeq ($(ARCH),x86_64)
402        SRCARCH := x86
403endif
404
405# Additional ARCH settings for sparc
406ifeq ($(ARCH),sparc32)
407       SRCARCH := sparc
408endif
409ifeq ($(ARCH),sparc64)
410       SRCARCH := sparc
411endif
412
413# Additional ARCH settings for parisc
414ifeq ($(ARCH),parisc64)
415       SRCARCH := parisc
416endif
417
418export cross_compiling :=
419ifneq ($(SRCARCH),$(SUBARCH))
420cross_compiling := 1
421endif
422
423KCONFIG_CONFIG	?= .config
424export KCONFIG_CONFIG
425
426# SHELL used by kbuild
427CONFIG_SHELL := sh
428
429HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS 2>/dev/null)
430HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS 2>/dev/null)
431HOST_LFS_LIBS := $(shell getconf LFS_LIBS 2>/dev/null)
432
433ifneq ($(LLVM),)
434ifneq ($(filter %/,$(LLVM)),)
435LLVM_PREFIX := $(LLVM)
436else ifneq ($(filter -%,$(LLVM)),)
437LLVM_SUFFIX := $(LLVM)
438endif
439
440HOSTCC	= $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
441HOSTCXX	= $(LLVM_PREFIX)clang++$(LLVM_SUFFIX)
442else
443HOSTCC	= gcc
444HOSTCXX	= g++
445endif
446HOSTRUSTC = rustc
447HOSTPKG_CONFIG	= pkg-config
448
449KBUILD_USERHOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
450			 -O2 -fomit-frame-pointer -std=gnu11
451KBUILD_USERCFLAGS  := $(KBUILD_USERHOSTCFLAGS) $(USERCFLAGS)
452KBUILD_USERLDFLAGS := $(USERLDFLAGS)
453
454# These flags apply to all Rust code in the tree, including the kernel and
455# host programs.
456export rust_common_flags := --edition=2021 \
457			    -Zbinary_dep_depinfo=y \
458			    -Dunsafe_op_in_unsafe_fn -Drust_2018_idioms \
459			    -Dunreachable_pub -Dnon_ascii_idents \
460			    -Wmissing_docs \
461			    -Drustdoc::missing_crate_level_docs \
462			    -Dclippy::correctness -Dclippy::style \
463			    -Dclippy::suspicious -Dclippy::complexity \
464			    -Dclippy::perf \
465			    -Dclippy::let_unit_value -Dclippy::mut_mut \
466			    -Dclippy::needless_bitwise_bool \
467			    -Dclippy::needless_continue \
468			    -Wclippy::dbg_macro
469
470KBUILD_HOSTCFLAGS   := $(KBUILD_USERHOSTCFLAGS) $(HOST_LFS_CFLAGS) $(HOSTCFLAGS)
471KBUILD_HOSTCXXFLAGS := -Wall -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS)
472KBUILD_HOSTRUSTFLAGS := $(rust_common_flags) -O -Cstrip=debuginfo \
473			-Zallow-features= $(HOSTRUSTFLAGS)
474KBUILD_HOSTLDFLAGS  := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
475KBUILD_HOSTLDLIBS   := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
476
477# Make variables (CC, etc...)
478CPP		= $(CC) -E
479ifneq ($(LLVM),)
480CC		= $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
481LD		= $(LLVM_PREFIX)ld.lld$(LLVM_SUFFIX)
482AR		= $(LLVM_PREFIX)llvm-ar$(LLVM_SUFFIX)
483NM		= $(LLVM_PREFIX)llvm-nm$(LLVM_SUFFIX)
484OBJCOPY		= $(LLVM_PREFIX)llvm-objcopy$(LLVM_SUFFIX)
485OBJDUMP		= $(LLVM_PREFIX)llvm-objdump$(LLVM_SUFFIX)
486READELF		= $(LLVM_PREFIX)llvm-readelf$(LLVM_SUFFIX)
487STRIP		= $(LLVM_PREFIX)llvm-strip$(LLVM_SUFFIX)
488else
489CC		= $(CROSS_COMPILE)gcc
490LD		= $(CROSS_COMPILE)ld
491AR		= $(CROSS_COMPILE)ar
492NM		= $(CROSS_COMPILE)nm
493OBJCOPY		= $(CROSS_COMPILE)objcopy
494OBJDUMP		= $(CROSS_COMPILE)objdump
495READELF		= $(CROSS_COMPILE)readelf
496STRIP		= $(CROSS_COMPILE)strip
497endif
498RUSTC		= rustc
499RUSTDOC		= rustdoc
500RUSTFMT		= rustfmt
501CLIPPY_DRIVER	= clippy-driver
502BINDGEN		= bindgen
503CARGO		= cargo
504PAHOLE		= pahole
505RESOLVE_BTFIDS	= $(objtree)/tools/bpf/resolve_btfids/resolve_btfids
506LEX		= flex
507YACC		= bison
508AWK		= awk
509INSTALLKERNEL  := installkernel
510DEPMOD		= depmod
511PERL		= perl
512PYTHON3		= python3
513CHECK		= sparse
514BASH		= bash
515KGZIP		= gzip
516KBZIP2		= bzip2
517KLZOP		= lzop
518LZMA		= lzma
519LZ4		= lz4c
520XZ		= xz
521ZSTD		= zstd
522
523PAHOLE_FLAGS	= $(shell PAHOLE=$(PAHOLE) $(srctree)/scripts/pahole-flags.sh)
524
525CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
526		  -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
527NOSTDINC_FLAGS :=
528CFLAGS_MODULE   =
529RUSTFLAGS_MODULE =
530AFLAGS_MODULE   =
531LDFLAGS_MODULE  =
532CFLAGS_KERNEL	=
533RUSTFLAGS_KERNEL =
534AFLAGS_KERNEL	=
535LDFLAGS_vmlinux =
536
537# Use USERINCLUDE when you must reference the UAPI directories only.
538USERINCLUDE    := \
539		-I$(srctree)/arch/$(SRCARCH)/include/uapi \
540		-I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
541		-I$(srctree)/include/uapi \
542		-I$(objtree)/include/generated/uapi \
543                -include $(srctree)/include/linux/compiler-version.h \
544                -include $(srctree)/include/linux/kconfig.h
545
546# Use LINUXINCLUDE when you must reference the include/ directory.
547# Needed to be compatible with the O= option
548LINUXINCLUDE    := \
549		-I$(srctree)/arch/$(SRCARCH)/include \
550		-I$(objtree)/arch/$(SRCARCH)/include/generated \
551		$(if $(building_out_of_srctree),-I$(srctree)/include) \
552		-I$(objtree)/include \
553		$(USERINCLUDE)
554
555KBUILD_AFLAGS   := -D__ASSEMBLY__ -fno-PIE
556KBUILD_CFLAGS   := -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs \
557		   -fno-strict-aliasing -fno-common -fshort-wchar -fno-PIE \
558		   -Werror=implicit-function-declaration -Werror=implicit-int \
559		   -Werror=return-type -Wno-format-security -funsigned-char \
560		   -std=gnu11
561KBUILD_CPPFLAGS := -D__KERNEL__
562KBUILD_RUSTFLAGS := $(rust_common_flags) \
563		    --target=$(objtree)/scripts/target.json \
564		    -Cpanic=abort -Cembed-bitcode=n -Clto=n \
565		    -Cforce-unwind-tables=n -Ccodegen-units=1 \
566		    -Csymbol-mangling-version=v0 \
567		    -Crelocation-model=static \
568		    -Zfunction-sections=n \
569		    -Dclippy::float_arithmetic
570
571KBUILD_AFLAGS_KERNEL :=
572KBUILD_CFLAGS_KERNEL :=
573KBUILD_RUSTFLAGS_KERNEL :=
574KBUILD_AFLAGS_MODULE  := -DMODULE
575KBUILD_CFLAGS_MODULE  := -DMODULE
576KBUILD_RUSTFLAGS_MODULE := --cfg MODULE
577KBUILD_LDFLAGS_MODULE :=
578KBUILD_LDFLAGS :=
579CLANG_FLAGS :=
580
581ifeq ($(KBUILD_CLIPPY),1)
582	RUSTC_OR_CLIPPY_QUIET := CLIPPY
583	RUSTC_OR_CLIPPY = $(CLIPPY_DRIVER)
584else
585	RUSTC_OR_CLIPPY_QUIET := RUSTC
586	RUSTC_OR_CLIPPY = $(RUSTC)
587endif
588
589ifdef RUST_LIB_SRC
590	export RUST_LIB_SRC
591endif
592
593# Allows the usage of unstable features in stable compilers.
594export RUSTC_BOOTSTRAP := 1
595
596export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE LD CC HOSTPKG_CONFIG
597export RUSTC RUSTDOC RUSTFMT RUSTC_OR_CLIPPY_QUIET RUSTC_OR_CLIPPY BINDGEN CARGO
598export HOSTRUSTC KBUILD_HOSTRUSTFLAGS
599export CPP AR NM STRIP OBJCOPY OBJDUMP READELF PAHOLE RESOLVE_BTFIDS LEX YACC AWK INSTALLKERNEL
600export PERL PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
601export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD
602export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE
603export KBUILD_USERCFLAGS KBUILD_USERLDFLAGS
604
605export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
606export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
607export KBUILD_RUSTFLAGS RUSTFLAGS_KERNEL RUSTFLAGS_MODULE
608export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
609export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_RUSTFLAGS_MODULE KBUILD_LDFLAGS_MODULE
610export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL KBUILD_RUSTFLAGS_KERNEL
611export PAHOLE_FLAGS
612
613# Files to ignore in find ... statements
614
615export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o    \
616			  -name CVS -o -name .pc -o -name .hg -o -name .git \) \
617			  -prune -o
618export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
619			 --exclude CVS --exclude .pc --exclude .hg --exclude .git
620
621# ===========================================================================
622# Rules shared between *config targets and build targets
623
624# Basic helpers built in scripts/basic/
625PHONY += scripts_basic
626scripts_basic:
627	$(Q)$(MAKE) $(build)=scripts/basic
628
629PHONY += outputmakefile
630ifdef building_out_of_srctree
631# Before starting out-of-tree build, make sure the source tree is clean.
632# outputmakefile generates a Makefile in the output directory, if using a
633# separate output directory. This allows convenient use of make in the
634# output directory.
635# At the same time when output Makefile generated, generate .gitignore to
636# ignore whole output directory
637
638quiet_cmd_makefile = GEN     Makefile
639      cmd_makefile = { \
640	echo "\# Automatically generated by $(srctree)/Makefile: don't edit"; \
641	echo "include $(srctree)/Makefile"; \
642	} > Makefile
643
644outputmakefile:
645	@if [ -f $(srctree)/.config -o \
646		 -d $(srctree)/include/config -o \
647		 -d $(srctree)/arch/$(SRCARCH)/include/generated ]; then \
648		echo >&2 "***"; \
649		echo >&2 "*** The source tree is not clean, please run 'make$(if $(findstring command line, $(origin ARCH)), ARCH=$(ARCH)) mrproper'"; \
650		echo >&2 "*** in $(abs_srctree)";\
651		echo >&2 "***"; \
652		false; \
653	fi
654	$(Q)ln -fsn $(srctree) source
655	$(call cmd,makefile)
656	$(Q)test -e .gitignore || \
657	{ echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
658endif
659
660# The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
661# Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
662# CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
663# and from include/config/auto.conf.cmd to detect the compiler upgrade.
664CC_VERSION_TEXT = $(subst $(pound),,$(shell LC_ALL=C $(CC) --version 2>/dev/null | head -n 1))
665
666ifneq ($(findstring clang,$(CC_VERSION_TEXT)),)
667include $(srctree)/scripts/Makefile.clang
668endif
669
670# Include this also for config targets because some architectures need
671# cc-cross-prefix to determine CROSS_COMPILE.
672ifdef need-compiler
673include $(srctree)/scripts/Makefile.compiler
674endif
675
676ifdef config-build
677# ===========================================================================
678# *config targets only - make sure prerequisites are updated, and descend
679# in scripts/kconfig to make the *config target
680
681# Read arch specific Makefile to set KBUILD_DEFCONFIG as needed.
682# KBUILD_DEFCONFIG may point out an alternative default configuration
683# used for 'make defconfig'
684include $(srctree)/arch/$(SRCARCH)/Makefile
685export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT
686
687config: outputmakefile scripts_basic FORCE
688	$(Q)$(MAKE) $(build)=scripts/kconfig $@
689
690%config: outputmakefile scripts_basic FORCE
691	$(Q)$(MAKE) $(build)=scripts/kconfig $@
692
693else #!config-build
694# ===========================================================================
695# Build targets only - this includes vmlinux, arch specific targets, clean
696# targets and others. In general all targets except *config targets.
697
698# If building an external module we do not care about the all: rule
699# but instead __all depend on modules
700PHONY += all
701ifeq ($(KBUILD_EXTMOD),)
702__all: all
703else
704__all: modules
705endif
706
707targets :=
708
709# Decide whether to build built-in, modular, or both.
710# Normally, just do built-in.
711
712KBUILD_MODULES :=
713KBUILD_BUILTIN := 1
714
715# If we have only "make modules", don't compile built-in objects.
716ifeq ($(MAKECMDGOALS),modules)
717  KBUILD_BUILTIN :=
718endif
719
720# If we have "make <whatever> modules", compile modules
721# in addition to whatever we do anyway.
722# Just "make" or "make all" shall build modules as well
723
724ifneq ($(filter all modules nsdeps %compile_commands.json clang-%,$(MAKECMDGOALS)),)
725  KBUILD_MODULES := 1
726endif
727
728ifeq ($(MAKECMDGOALS),)
729  KBUILD_MODULES := 1
730endif
731
732export KBUILD_MODULES KBUILD_BUILTIN
733
734ifdef need-config
735include include/config/auto.conf
736endif
737
738ifeq ($(KBUILD_EXTMOD),)
739# Objects we will link into vmlinux / subdirs we need to visit
740core-y		:=
741drivers-y	:=
742libs-y		:= lib/
743endif # KBUILD_EXTMOD
744
745# The all: target is the default when no target is given on the
746# command line.
747# This allow a user to issue only 'make' to build a kernel including modules
748# Defaults to vmlinux, but the arch makefile usually adds further targets
749all: vmlinux
750
751CFLAGS_GCOV	:= -fprofile-arcs -ftest-coverage
752ifdef CONFIG_CC_IS_GCC
753CFLAGS_GCOV	+= -fno-tree-loop-im
754endif
755export CFLAGS_GCOV
756
757# The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
758ifdef CONFIG_FUNCTION_TRACER
759  CC_FLAGS_FTRACE := -pg
760endif
761
762include $(srctree)/arch/$(SRCARCH)/Makefile
763
764ifdef need-config
765ifdef may-sync-config
766# Read in dependencies to all Kconfig* files, make sure to run syncconfig if
767# changes are detected. This should be included after arch/$(SRCARCH)/Makefile
768# because some architectures define CROSS_COMPILE there.
769include include/config/auto.conf.cmd
770
771$(KCONFIG_CONFIG):
772	@echo >&2 '***'
773	@echo >&2 '*** Configuration file "$@" not found!'
774	@echo >&2 '***'
775	@echo >&2 '*** Please run some configurator (e.g. "make oldconfig" or'
776	@echo >&2 '*** "make menuconfig" or "make xconfig").'
777	@echo >&2 '***'
778	@/bin/false
779
780# The actual configuration files used during the build are stored in
781# include/generated/ and include/config/. Update them if .config is newer than
782# include/config/auto.conf (which mirrors .config).
783#
784# This exploits the 'multi-target pattern rule' trick.
785# The syncconfig should be executed only once to make all the targets.
786# (Note: use the grouped target '&:' when we bump to GNU Make 4.3)
787#
788# Do not use $(call cmd,...) here. That would suppress prompts from syncconfig,
789# so you cannot notice that Kconfig is waiting for the user input.
790%/config/auto.conf %/config/auto.conf.cmd %/generated/autoconf.h %/generated/rustc_cfg: $(KCONFIG_CONFIG)
791	$(Q)$(kecho) "  SYNC    $@"
792	$(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
793else # !may-sync-config
794# External modules and some install targets need include/generated/autoconf.h
795# and include/config/auto.conf but do not care if they are up-to-date.
796# Use auto.conf to trigger the test
797PHONY += include/config/auto.conf
798
799include/config/auto.conf:
800	@test -e include/generated/autoconf.h -a -e $@ || (		\
801	echo >&2;							\
802	echo >&2 "  ERROR: Kernel configuration is invalid.";		\
803	echo >&2 "         include/generated/autoconf.h or $@ are missing.";\
804	echo >&2 "         Run 'make oldconfig && make prepare' on kernel src to fix it.";	\
805	echo >&2 ;							\
806	/bin/false)
807
808endif # may-sync-config
809endif # need-config
810
811KBUILD_CFLAGS	+= -fno-delete-null-pointer-checks
812KBUILD_CFLAGS	+= $(call cc-disable-warning,frame-address,)
813KBUILD_CFLAGS	+= $(call cc-disable-warning, format-truncation)
814KBUILD_CFLAGS	+= $(call cc-disable-warning, format-overflow)
815KBUILD_CFLAGS	+= $(call cc-disable-warning, address-of-packed-member)
816
817ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE
818KBUILD_CFLAGS += -O2
819KBUILD_RUSTFLAGS += -Copt-level=2
820else ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
821KBUILD_CFLAGS += -Os
822KBUILD_RUSTFLAGS += -Copt-level=s
823endif
824
825# Always set `debug-assertions` and `overflow-checks` because their default
826# depends on `opt-level` and `debug-assertions`, respectively.
827KBUILD_RUSTFLAGS += -Cdebug-assertions=$(if $(CONFIG_RUST_DEBUG_ASSERTIONS),y,n)
828KBUILD_RUSTFLAGS += -Coverflow-checks=$(if $(CONFIG_RUST_OVERFLOW_CHECKS),y,n)
829
830# Tell gcc to never replace conditional load with a non-conditional one
831ifdef CONFIG_CC_IS_GCC
832# gcc-10 renamed --param=allow-store-data-races=0 to
833# -fno-allow-store-data-races.
834KBUILD_CFLAGS	+= $(call cc-option,--param=allow-store-data-races=0)
835KBUILD_CFLAGS	+= $(call cc-option,-fno-allow-store-data-races)
836endif
837
838ifdef CONFIG_READABLE_ASM
839# Disable optimizations that make assembler listings hard to read.
840# reorder blocks reorders the control in the function
841# ipa clone creates specialized cloned functions
842# partial inlining inlines only parts of functions
843KBUILD_CFLAGS += -fno-reorder-blocks -fno-ipa-cp-clone -fno-partial-inlining
844endif
845
846ifneq ($(CONFIG_FRAME_WARN),0)
847KBUILD_CFLAGS += -Wframe-larger-than=$(CONFIG_FRAME_WARN)
848endif
849
850stackp-flags-y                                    := -fno-stack-protector
851stackp-flags-$(CONFIG_STACKPROTECTOR)             := -fstack-protector
852stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG)      := -fstack-protector-strong
853
854KBUILD_CFLAGS += $(stackp-flags-y)
855
856KBUILD_CPPFLAGS-$(CONFIG_WERROR) += -Werror
857KBUILD_CPPFLAGS += $(KBUILD_CPPFLAGS-y)
858KBUILD_CFLAGS-$(CONFIG_CC_NO_ARRAY_BOUNDS) += -Wno-array-bounds
859
860KBUILD_RUSTFLAGS-$(CONFIG_WERROR) += -Dwarnings
861KBUILD_RUSTFLAGS += $(KBUILD_RUSTFLAGS-y)
862
863ifdef CONFIG_CC_IS_CLANG
864# The kernel builds with '-std=gnu11' so use of GNU extensions is acceptable.
865KBUILD_CFLAGS += -Wno-gnu
866else
867
868# gcc inanely warns about local variables called 'main'
869KBUILD_CFLAGS += -Wno-main
870endif
871
872# These warnings generated too much noise in a regular build.
873# Use make W=1 to enable them (see scripts/Makefile.extrawarn)
874KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
875KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
876
877# These result in bogus false positives
878KBUILD_CFLAGS += $(call cc-disable-warning, dangling-pointer)
879
880ifdef CONFIG_FRAME_POINTER
881KBUILD_CFLAGS	+= -fno-omit-frame-pointer -fno-optimize-sibling-calls
882KBUILD_RUSTFLAGS += -Cforce-frame-pointers=y
883else
884# Some targets (ARM with Thumb2, for example), can't be built with frame
885# pointers.  For those, we don't have FUNCTION_TRACER automatically
886# select FRAME_POINTER.  However, FUNCTION_TRACER adds -pg, and this is
887# incompatible with -fomit-frame-pointer with current GCC, so we don't use
888# -fomit-frame-pointer with FUNCTION_TRACER.
889# In the Rust target specification, "frame-pointer" is set explicitly
890# to "may-omit".
891ifndef CONFIG_FUNCTION_TRACER
892KBUILD_CFLAGS	+= -fomit-frame-pointer
893endif
894endif
895
896# Initialize all stack variables with a 0xAA pattern.
897ifdef CONFIG_INIT_STACK_ALL_PATTERN
898KBUILD_CFLAGS	+= -ftrivial-auto-var-init=pattern
899endif
900
901# Initialize all stack variables with a zero value.
902ifdef CONFIG_INIT_STACK_ALL_ZERO
903KBUILD_CFLAGS	+= -ftrivial-auto-var-init=zero
904ifdef CONFIG_CC_HAS_AUTO_VAR_INIT_ZERO_ENABLER
905# https://github.com/llvm/llvm-project/issues/44842
906CC_AUTO_VAR_INIT_ZERO_ENABLER := -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang
907export CC_AUTO_VAR_INIT_ZERO_ENABLER
908KBUILD_CFLAGS	+= $(CC_AUTO_VAR_INIT_ZERO_ENABLER)
909endif
910endif
911
912# While VLAs have been removed, GCC produces unreachable stack probes
913# for the randomize_kstack_offset feature. Disable it for all compilers.
914KBUILD_CFLAGS	+= $(call cc-option, -fno-stack-clash-protection)
915
916# Clear used registers at func exit (to reduce data lifetime and ROP gadgets).
917ifdef CONFIG_ZERO_CALL_USED_REGS
918KBUILD_CFLAGS	+= -fzero-call-used-regs=used-gpr
919endif
920
921ifdef CONFIG_FUNCTION_TRACER
922ifdef CONFIG_FTRACE_MCOUNT_USE_CC
923  CC_FLAGS_FTRACE	+= -mrecord-mcount
924  ifdef CONFIG_HAVE_NOP_MCOUNT
925    ifeq ($(call cc-option-yn, -mnop-mcount),y)
926      CC_FLAGS_FTRACE	+= -mnop-mcount
927      CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
928    endif
929  endif
930endif
931ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
932  ifdef CONFIG_HAVE_OBJTOOL_NOP_MCOUNT
933    CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
934  endif
935endif
936ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
937  ifdef CONFIG_HAVE_C_RECORDMCOUNT
938    BUILD_C_RECORDMCOUNT := y
939    export BUILD_C_RECORDMCOUNT
940  endif
941endif
942ifdef CONFIG_HAVE_FENTRY
943  # s390-linux-gnu-gcc did not support -mfentry until gcc-9.
944  ifeq ($(call cc-option-yn, -mfentry),y)
945    CC_FLAGS_FTRACE	+= -mfentry
946    CC_FLAGS_USING	+= -DCC_USING_FENTRY
947  endif
948endif
949export CC_FLAGS_FTRACE
950KBUILD_CFLAGS	+= $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
951KBUILD_AFLAGS	+= $(CC_FLAGS_USING)
952endif
953
954# We trigger additional mismatches with less inlining
955ifdef CONFIG_DEBUG_SECTION_MISMATCH
956KBUILD_CFLAGS += -fno-inline-functions-called-once
957endif
958
959# `rustc`'s `-Zfunction-sections` applies to data too (as of 1.59.0).
960ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
961KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
962KBUILD_RUSTFLAGS_KERNEL += -Zfunction-sections=y
963LDFLAGS_vmlinux += --gc-sections
964endif
965
966ifdef CONFIG_SHADOW_CALL_STACK
967ifndef CONFIG_DYNAMIC_SCS
968CC_FLAGS_SCS	:= -fsanitize=shadow-call-stack
969KBUILD_CFLAGS	+= $(CC_FLAGS_SCS)
970endif
971export CC_FLAGS_SCS
972endif
973
974ifdef CONFIG_LTO_CLANG
975ifdef CONFIG_LTO_CLANG_THIN
976CC_FLAGS_LTO	:= -flto=thin -fsplit-lto-unit
977KBUILD_LDFLAGS	+= --thinlto-cache-dir=$(extmod_prefix).thinlto-cache
978else
979CC_FLAGS_LTO	:= -flto
980endif
981CC_FLAGS_LTO	+= -fvisibility=hidden
982
983# Limit inlining across translation units to reduce binary size
984KBUILD_LDFLAGS += -mllvm -import-instr-limit=5
985
986# Check for frame size exceeding threshold during prolog/epilog insertion
987# when using lld < 13.0.0.
988ifneq ($(CONFIG_FRAME_WARN),0)
989ifeq ($(call test-lt, $(CONFIG_LLD_VERSION), 130000),y)
990KBUILD_LDFLAGS	+= -plugin-opt=-warn-stack-size=$(CONFIG_FRAME_WARN)
991endif
992endif
993endif
994
995ifdef CONFIG_LTO
996KBUILD_CFLAGS	+= -fno-lto $(CC_FLAGS_LTO)
997KBUILD_AFLAGS	+= -fno-lto
998export CC_FLAGS_LTO
999endif
1000
1001ifdef CONFIG_CFI_CLANG
1002CC_FLAGS_CFI	:= -fsanitize=kcfi
1003KBUILD_CFLAGS	+= $(CC_FLAGS_CFI)
1004export CC_FLAGS_CFI
1005endif
1006
1007ifneq ($(CONFIG_FUNCTION_ALIGNMENT),0)
1008KBUILD_CFLAGS += -falign-functions=$(CONFIG_FUNCTION_ALIGNMENT)
1009endif
1010
1011# arch Makefile may override CC so keep this after arch Makefile is included
1012NOSTDINC_FLAGS += -nostdinc
1013
1014# Variable Length Arrays (VLAs) should not be used anywhere in the kernel
1015KBUILD_CFLAGS += -Wvla
1016
1017# disable pointer signed / unsigned warnings in gcc 4.0
1018KBUILD_CFLAGS += -Wno-pointer-sign
1019
1020# In order to make sure new function cast mismatches are not introduced
1021# in the kernel (to avoid tripping CFI checking), the kernel should be
1022# globally built with -Wcast-function-type.
1023KBUILD_CFLAGS += $(call cc-option, -Wcast-function-type)
1024
1025# disable stringop warnings in gcc 8+
1026KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation)
1027
1028# We'll want to enable this eventually, but it's not going away for 5.7 at least
1029KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow)
1030
1031# Another good warning that we'll want to enable eventually
1032KBUILD_CFLAGS += $(call cc-disable-warning, restrict)
1033
1034# Enabled with W=2, disabled by default as noisy
1035ifdef CONFIG_CC_IS_GCC
1036KBUILD_CFLAGS += -Wno-maybe-uninitialized
1037endif
1038
1039# The allocators already balk at large sizes, so silence the compiler
1040# warnings for bounds checks involving those possible values. While
1041# -Wno-alloc-size-larger-than would normally be used here, earlier versions
1042# of gcc (<9.1) weirdly don't handle the option correctly when _other_
1043# warnings are produced (?!). Using -Walloc-size-larger-than=SIZE_MAX
1044# doesn't work (as it is documented to), silently resolving to "0" prior to
1045# version 9.1 (and producing an error more recently). Numeric values larger
1046# than PTRDIFF_MAX also don't work prior to version 9.1, which are silently
1047# ignored, continuing to default to PTRDIFF_MAX. So, left with no other
1048# choice, we must perform a versioned check to disable this warning.
1049# https://lore.kernel.org/lkml/20210824115859.187f272f@canb.auug.org.au
1050KBUILD_CFLAGS-$(call gcc-min-version, 90100) += -Wno-alloc-size-larger-than
1051KBUILD_CFLAGS += $(KBUILD_CFLAGS-y) $(CONFIG_CC_IMPLICIT_FALLTHROUGH)
1052
1053# disable invalid "can't wrap" optimizations for signed / pointers
1054KBUILD_CFLAGS	+= -fno-strict-overflow
1055
1056# Make sure -fstack-check isn't enabled (like gentoo apparently did)
1057KBUILD_CFLAGS  += -fno-stack-check
1058
1059# conserve stack if available
1060ifdef CONFIG_CC_IS_GCC
1061KBUILD_CFLAGS   += -fconserve-stack
1062endif
1063
1064# Prohibit date/time macros, which would make the build non-deterministic
1065KBUILD_CFLAGS   += -Werror=date-time
1066
1067# enforce correct pointer usage
1068KBUILD_CFLAGS   += $(call cc-option,-Werror=incompatible-pointer-types)
1069
1070# Require designated initializers for all marked structures
1071KBUILD_CFLAGS   += $(call cc-option,-Werror=designated-init)
1072
1073# change __FILE__ to the relative path from the srctree
1074KBUILD_CPPFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
1075
1076# include additional Makefiles when needed
1077include-y			:= scripts/Makefile.extrawarn
1078include-$(CONFIG_DEBUG_INFO)	+= scripts/Makefile.debug
1079include-$(CONFIG_KASAN)		+= scripts/Makefile.kasan
1080include-$(CONFIG_KCSAN)		+= scripts/Makefile.kcsan
1081include-$(CONFIG_KMSAN)		+= scripts/Makefile.kmsan
1082include-$(CONFIG_UBSAN)		+= scripts/Makefile.ubsan
1083include-$(CONFIG_KCOV)		+= scripts/Makefile.kcov
1084include-$(CONFIG_RANDSTRUCT)	+= scripts/Makefile.randstruct
1085include-$(CONFIG_GCC_PLUGINS)	+= scripts/Makefile.gcc-plugins
1086
1087include $(addprefix $(srctree)/, $(include-y))
1088
1089# scripts/Makefile.gcc-plugins is intentionally included last.
1090# Do not add $(call cc-option,...) below this line. When you build the kernel
1091# from the clean source tree, the GCC plugins do not exist at this point.
1092
1093# Add user supplied CPPFLAGS, AFLAGS, CFLAGS and RUSTFLAGS as the last assignments
1094KBUILD_CPPFLAGS += $(KCPPFLAGS)
1095KBUILD_AFLAGS   += $(KAFLAGS)
1096KBUILD_CFLAGS   += $(KCFLAGS)
1097KBUILD_RUSTFLAGS += $(KRUSTFLAGS)
1098
1099KBUILD_LDFLAGS_MODULE += --build-id=sha1
1100LDFLAGS_vmlinux += --build-id=sha1
1101
1102KBUILD_LDFLAGS	+= -z noexecstack
1103ifeq ($(CONFIG_LD_IS_BFD),y)
1104KBUILD_LDFLAGS	+= $(call ld-option,--no-warn-rwx-segments)
1105endif
1106
1107ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
1108LDFLAGS_vmlinux	+= -X
1109endif
1110
1111ifeq ($(CONFIG_RELR),y)
1112# ld.lld before 15 did not support -z pack-relative-relocs.
1113LDFLAGS_vmlinux	+= $(call ld-option,--pack-dyn-relocs=relr,-z pack-relative-relocs)
1114endif
1115
1116# We never want expected sections to be placed heuristically by the
1117# linker. All sections should be explicitly named in the linker script.
1118ifdef CONFIG_LD_ORPHAN_WARN
1119LDFLAGS_vmlinux += --orphan-handling=$(CONFIG_LD_ORPHAN_WARN_LEVEL)
1120endif
1121
1122# Align the bit size of userspace programs with the kernel
1123KBUILD_USERCFLAGS  += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1124KBUILD_USERLDFLAGS += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1125
1126# make the checker run with the right architecture
1127CHECKFLAGS += --arch=$(ARCH)
1128
1129# insure the checker run with the right endianness
1130CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
1131
1132# the checker needs the correct machine size
1133CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
1134
1135# Default kernel image to build when no specific target is given.
1136# KBUILD_IMAGE may be overruled on the command line or
1137# set in the environment
1138# Also any assignments in arch/$(ARCH)/Makefile take precedence over
1139# this default value
1140export KBUILD_IMAGE ?= vmlinux
1141
1142#
1143# INSTALL_PATH specifies where to place the updated kernel and system map
1144# images. Default is /boot, but you can set it to other values
1145export	INSTALL_PATH ?= /boot
1146
1147#
1148# INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
1149# Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
1150# an argument if needed. Otherwise it defaults to the kernel install path
1151#
1152export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
1153
1154#
1155# INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
1156# relocations required by build roots.  This is not defined in the
1157# makefile but the argument can be passed to make if needed.
1158#
1159
1160MODLIB	= $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
1161export MODLIB
1162
1163PHONY += prepare0
1164
1165export extmod_prefix = $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/)
1166export MODORDER := $(extmod_prefix)modules.order
1167export MODULES_NSDEPS := $(extmod_prefix)modules.nsdeps
1168
1169ifeq ($(KBUILD_EXTMOD),)
1170
1171build-dir	:= .
1172clean-dirs	:= $(sort . Documentation \
1173		     $(patsubst %/,%,$(filter %/, $(core-) \
1174			$(drivers-) $(libs-))))
1175
1176export ARCH_CORE	:= $(core-y)
1177export ARCH_LIB		:= $(filter %/, $(libs-y))
1178export ARCH_DRIVERS	:= $(drivers-y) $(drivers-m)
1179# Externally visible symbols (used by link-vmlinux.sh)
1180
1181KBUILD_VMLINUX_OBJS := ./built-in.a
1182ifdef CONFIG_MODULES
1183KBUILD_VMLINUX_OBJS += $(patsubst %/, %/lib.a, $(filter %/, $(libs-y)))
1184KBUILD_VMLINUX_LIBS := $(filter-out %/, $(libs-y))
1185else
1186KBUILD_VMLINUX_LIBS := $(patsubst %/,%/lib.a, $(libs-y))
1187endif
1188
1189export KBUILD_VMLINUX_LIBS
1190export KBUILD_LDS          := arch/$(SRCARCH)/kernel/vmlinux.lds
1191
1192# Recurse until adjust_autoksyms.sh is satisfied
1193PHONY += autoksyms_recursive
1194ifdef CONFIG_TRIM_UNUSED_KSYMS
1195# For the kernel to actually contain only the needed exported symbols,
1196# we have to build modules as well to determine what those symbols are.
1197# (this can be evaluated only once include/config/auto.conf has been included)
1198KBUILD_MODULES := 1
1199
1200autoksyms_recursive: $(build-dir) modules.order
1201	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \
1202	  "$(MAKE) -f $(srctree)/Makefile autoksyms_recursive"
1203endif
1204
1205autoksyms_h := $(if $(CONFIG_TRIM_UNUSED_KSYMS), include/generated/autoksyms.h)
1206
1207quiet_cmd_autoksyms_h = GEN     $@
1208      cmd_autoksyms_h = mkdir -p $(dir $@); \
1209			$(CONFIG_SHELL) $(srctree)/scripts/gen_autoksyms.sh $@
1210
1211$(autoksyms_h):
1212	$(call cmd,autoksyms_h)
1213
1214# '$(AR) mPi' needs 'T' to workaround the bug of llvm-ar <= 14
1215quiet_cmd_ar_vmlinux.a = AR      $@
1216      cmd_ar_vmlinux.a = \
1217	rm -f $@; \
1218	$(AR) cDPrST $@ $(KBUILD_VMLINUX_OBJS); \
1219	$(AR) mPiT $$($(AR) t $@ | sed -n 1p) $@ $$($(AR) t $@ | grep -F -f $(srctree)/scripts/head-object-list.txt)
1220
1221targets += vmlinux.a
1222vmlinux.a: $(KBUILD_VMLINUX_OBJS) scripts/head-object-list.txt autoksyms_recursive FORCE
1223	$(call if_changed,ar_vmlinux.a)
1224
1225PHONY += vmlinux_o
1226vmlinux_o: vmlinux.a $(KBUILD_VMLINUX_LIBS)
1227	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux_o
1228
1229vmlinux.o modules.builtin.modinfo modules.builtin: vmlinux_o
1230	@:
1231
1232PHONY += vmlinux
1233# LDFLAGS_vmlinux in the top Makefile defines linker flags for the top vmlinux,
1234# not for decompressors. LDFLAGS_vmlinux in arch/*/boot/compressed/Makefile is
1235# unrelated; the decompressors just happen to have the same base name,
1236# arch/*/boot/compressed/vmlinux.
1237# Export LDFLAGS_vmlinux only to scripts/Makefile.vmlinux.
1238#
1239# _LDFLAGS_vmlinux is a workaround for the 'private export' bug:
1240#   https://savannah.gnu.org/bugs/?61463
1241# For Make > 4.4, the following simple code will work:
1242#  vmlinux: private export LDFLAGS_vmlinux := $(LDFLAGS_vmlinux)
1243vmlinux: private _LDFLAGS_vmlinux := $(LDFLAGS_vmlinux)
1244vmlinux: export LDFLAGS_vmlinux = $(_LDFLAGS_vmlinux)
1245vmlinux: vmlinux.o $(KBUILD_LDS) modpost
1246	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux
1247
1248# The actual objects are generated when descending,
1249# make sure no implicit rule kicks in
1250$(sort $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)): . ;
1251
1252ifeq ($(origin KERNELRELEASE),file)
1253filechk_kernel.release = $(srctree)/scripts/setlocalversion $(srctree)
1254else
1255filechk_kernel.release = echo $(KERNELRELEASE)
1256endif
1257
1258# Store (new) KERNELRELEASE string in include/config/kernel.release
1259include/config/kernel.release: FORCE
1260	$(call filechk,kernel.release)
1261
1262# Additional helpers built in scripts/
1263# Carefully list dependencies so we do not try to build scripts twice
1264# in parallel
1265PHONY += scripts
1266scripts: scripts_basic scripts_dtc
1267	$(Q)$(MAKE) $(build)=$(@)
1268
1269# Things we need to do before we recursively start building the kernel
1270# or the modules are listed in "prepare".
1271# A multi level approach is used. prepareN is processed before prepareN-1.
1272# archprepare is used in arch Makefiles and when processed asm symlink,
1273# version.h and scripts_basic is processed / created.
1274
1275PHONY += prepare archprepare
1276
1277archprepare: outputmakefile archheaders archscripts scripts include/config/kernel.release \
1278	asm-generic $(version_h) $(autoksyms_h) include/generated/utsrelease.h \
1279	include/generated/compile.h include/generated/autoconf.h remove-stale-files
1280
1281prepare0: archprepare
1282	$(Q)$(MAKE) $(build)=scripts/mod
1283	$(Q)$(MAKE) $(build)=. prepare
1284
1285# All the preparing..
1286prepare: prepare0
1287ifdef CONFIG_RUST
1288	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh -v
1289	$(Q)$(MAKE) $(build)=rust
1290endif
1291
1292PHONY += remove-stale-files
1293remove-stale-files:
1294	$(Q)$(srctree)/scripts/remove-stale-files
1295
1296# Support for using generic headers in asm-generic
1297asm-generic := -f $(srctree)/scripts/Makefile.asm-generic obj
1298
1299PHONY += asm-generic uapi-asm-generic
1300asm-generic: uapi-asm-generic
1301	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm \
1302	generic=include/asm-generic
1303uapi-asm-generic:
1304	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \
1305	generic=include/uapi/asm-generic
1306
1307# Generate some files
1308# ---------------------------------------------------------------------------
1309
1310# KERNELRELEASE can change from a few different places, meaning version.h
1311# needs to be updated, so this check is forced on all builds
1312
1313uts_len := 64
1314define filechk_utsrelease.h
1315	if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1316	  echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2;    \
1317	  exit 1;                                                         \
1318	fi;                                                               \
1319	echo \#define UTS_RELEASE \"$(KERNELRELEASE)\"
1320endef
1321
1322define filechk_version.h
1323	if [ $(SUBLEVEL) -gt 255 ]; then                                 \
1324		echo \#define LINUX_VERSION_CODE $(shell                 \
1325		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + 255); \
1326	else                                                             \
1327		echo \#define LINUX_VERSION_CODE $(shell                 \
1328		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + $(SUBLEVEL)); \
1329	fi;                                                              \
1330	echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) +  \
1331	((c) > 255 ? 255 : (c)))';                                       \
1332	echo \#define LINUX_VERSION_MAJOR $(VERSION);                    \
1333	echo \#define LINUX_VERSION_PATCHLEVEL $(PATCHLEVEL);            \
1334	echo \#define LINUX_VERSION_SUBLEVEL $(SUBLEVEL)
1335endef
1336
1337$(version_h): PATCHLEVEL := $(or $(PATCHLEVEL), 0)
1338$(version_h): SUBLEVEL := $(or $(SUBLEVEL), 0)
1339$(version_h): FORCE
1340	$(call filechk,version.h)
1341
1342include/generated/utsrelease.h: include/config/kernel.release FORCE
1343	$(call filechk,utsrelease.h)
1344
1345filechk_compile.h = $(srctree)/scripts/mkcompile_h \
1346	"$(UTS_MACHINE)" "$(CONFIG_CC_VERSION_TEXT)" "$(LD)"
1347
1348include/generated/compile.h: FORCE
1349	$(call filechk,compile.h)
1350
1351PHONY += headerdep
1352headerdep:
1353	$(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1354	$(srctree)/scripts/headerdep.pl -I$(srctree)/include
1355
1356# ---------------------------------------------------------------------------
1357# Kernel headers
1358
1359#Default location for installed headers
1360export INSTALL_HDR_PATH = $(objtree)/usr
1361
1362quiet_cmd_headers_install = INSTALL $(INSTALL_HDR_PATH)/include
1363      cmd_headers_install = \
1364	mkdir -p $(INSTALL_HDR_PATH); \
1365	rsync -mrl --include='*/' --include='*\.h' --exclude='*' \
1366	usr/include $(INSTALL_HDR_PATH)
1367
1368PHONY += headers_install
1369headers_install: headers
1370	$(call cmd,headers_install)
1371
1372PHONY += archheaders archscripts
1373
1374hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
1375
1376PHONY += headers
1377headers: $(version_h) scripts_unifdef uapi-asm-generic archheaders archscripts
1378	$(if $(filter um, $(SRCARCH)), $(error Headers not exportable for UML))
1379	$(Q)$(MAKE) $(hdr-inst)=include/uapi
1380	$(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi
1381
1382ifdef CONFIG_HEADERS_INSTALL
1383prepare: headers
1384endif
1385
1386PHONY += scripts_unifdef
1387scripts_unifdef: scripts_basic
1388	$(Q)$(MAKE) $(build)=scripts scripts/unifdef
1389
1390# ---------------------------------------------------------------------------
1391# Install
1392
1393# Many distributions have the custom install script, /sbin/installkernel.
1394# If DKMS is installed, 'make install' will eventually recurse back
1395# to this Makefile to build and install external modules.
1396# Cancel sub_make_done so that options such as M=, V=, etc. are parsed.
1397
1398quiet_cmd_install = INSTALL $(INSTALL_PATH)
1399      cmd_install = unset sub_make_done; $(srctree)/scripts/install.sh
1400
1401# ---------------------------------------------------------------------------
1402# Tools
1403
1404ifdef CONFIG_OBJTOOL
1405prepare: tools/objtool
1406endif
1407
1408ifdef CONFIG_BPF
1409ifdef CONFIG_DEBUG_INFO_BTF
1410prepare: tools/bpf/resolve_btfids
1411endif
1412endif
1413
1414PHONY += resolve_btfids_clean
1415
1416resolve_btfids_O = $(abspath $(objtree))/tools/bpf/resolve_btfids
1417
1418# tools/bpf/resolve_btfids directory might not exist
1419# in output directory, skip its clean in that case
1420resolve_btfids_clean:
1421ifneq ($(wildcard $(resolve_btfids_O)),)
1422	$(Q)$(MAKE) -sC $(srctree)/tools/bpf/resolve_btfids O=$(resolve_btfids_O) clean
1423endif
1424
1425# Clear a bunch of variables before executing the submake
1426ifeq ($(quiet),silent_)
1427tools_silent=s
1428endif
1429
1430tools/: FORCE
1431	$(Q)mkdir -p $(objtree)/tools
1432	$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/
1433
1434tools/%: FORCE
1435	$(Q)mkdir -p $(objtree)/tools
1436	$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/ $*
1437
1438# ---------------------------------------------------------------------------
1439# Kernel selftest
1440
1441PHONY += kselftest
1442kselftest: headers
1443	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1444
1445kselftest-%: headers FORCE
1446	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests $*
1447
1448PHONY += kselftest-merge
1449kselftest-merge:
1450	$(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1451	$(Q)find $(srctree)/tools/testing/selftests -name config | \
1452		xargs $(srctree)/scripts/kconfig/merge_config.sh -m $(objtree)/.config
1453	$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1454
1455# ---------------------------------------------------------------------------
1456# Devicetree files
1457
1458ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
1459dtstree := arch/$(SRCARCH)/boot/dts
1460endif
1461
1462ifneq ($(dtstree),)
1463
1464%.dtb: dtbs_prepare
1465	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1466
1467%.dtbo: dtbs_prepare
1468	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1469
1470PHONY += dtbs dtbs_prepare dtbs_install dtbs_check
1471dtbs: dtbs_prepare
1472	$(Q)$(MAKE) $(build)=$(dtstree)
1473
1474# include/config/kernel.release is actually needed when installing DTBs because
1475# INSTALL_DTBS_PATH contains $(KERNELRELEASE). However, we do not want to make
1476# dtbs_install depend on it as dtbs_install may run as root.
1477dtbs_prepare: include/config/kernel.release scripts_dtc
1478
1479ifneq ($(filter dtbs_check, $(MAKECMDGOALS)),)
1480export CHECK_DTBS=y
1481endif
1482
1483ifneq ($(CHECK_DTBS),)
1484dtbs_prepare: dt_binding_check
1485endif
1486
1487dtbs_check: dtbs
1488
1489dtbs_install:
1490	$(Q)$(MAKE) $(dtbinst)=$(dtstree) dst=$(INSTALL_DTBS_PATH)
1491
1492ifdef CONFIG_OF_EARLY_FLATTREE
1493all: dtbs
1494endif
1495
1496endif
1497
1498PHONY += scripts_dtc
1499scripts_dtc: scripts_basic
1500	$(Q)$(MAKE) $(build)=scripts/dtc
1501
1502ifneq ($(filter dt_binding_check, $(MAKECMDGOALS)),)
1503export CHECK_DT_BINDING=y
1504endif
1505
1506PHONY += dt_binding_check
1507dt_binding_check: scripts_dtc
1508	$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings
1509
1510PHONY += dt_compatible_check
1511dt_compatible_check: dt_binding_check
1512	$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings $@
1513
1514# ---------------------------------------------------------------------------
1515# Modules
1516
1517ifdef CONFIG_MODULES
1518
1519# By default, build modules as well
1520
1521all: modules
1522
1523# When we're building modules with modversions, we need to consider
1524# the built-in objects during the descend as well, in order to
1525# make sure the checksums are up to date before we record them.
1526ifdef CONFIG_MODVERSIONS
1527  KBUILD_BUILTIN := 1
1528endif
1529
1530# Build modules
1531#
1532
1533# *.ko are usually independent of vmlinux, but CONFIG_DEBUG_INFO_BTF_MODULES
1534# is an exception.
1535ifdef CONFIG_DEBUG_INFO_BTF_MODULES
1536KBUILD_BUILTIN := 1
1537modules: vmlinux
1538endif
1539
1540modules: modules_prepare
1541
1542# Target to prepare building external modules
1543modules_prepare: prepare
1544	$(Q)$(MAKE) $(build)=scripts scripts/module.lds
1545
1546export modules_sign_only :=
1547
1548ifeq ($(CONFIG_MODULE_SIG),y)
1549PHONY += modules_sign
1550modules_sign: modules_install
1551	@:
1552
1553# modules_sign is a subset of modules_install.
1554# 'make modules_install modules_sign' is equivalent to 'make modules_install'.
1555ifeq ($(filter modules_install,$(MAKECMDGOALS)),)
1556modules_sign_only := y
1557endif
1558endif
1559
1560modinst_pre :=
1561ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
1562modinst_pre := __modinst_pre
1563endif
1564
1565modules_install: $(modinst_pre)
1566PHONY += __modinst_pre
1567__modinst_pre:
1568	@rm -rf $(MODLIB)/kernel
1569	@rm -f $(MODLIB)/source
1570	@mkdir -p $(MODLIB)/kernel
1571	@ln -s $(abspath $(srctree)) $(MODLIB)/source
1572	@if [ ! $(objtree) -ef  $(MODLIB)/build ]; then \
1573		rm -f $(MODLIB)/build ; \
1574		ln -s $(CURDIR) $(MODLIB)/build ; \
1575	fi
1576	@sed 's:^\(.*\)\.o$$:kernel/\1.ko:' modules.order > $(MODLIB)/modules.order
1577	@cp -f modules.builtin $(MODLIB)/
1578	@cp -f $(objtree)/modules.builtin.modinfo $(MODLIB)/
1579
1580endif # CONFIG_MODULES
1581
1582###
1583# Cleaning is done on three levels.
1584# make clean     Delete most generated files
1585#                Leave enough to build external modules
1586# make mrproper  Delete the current configuration, and all generated files
1587# make distclean Remove editor backup files, patch leftover files and the like
1588
1589# Directories & files removed with 'make clean'
1590CLEAN_FILES += include/ksym vmlinux.symvers modules-only.symvers \
1591	       modules.builtin modules.builtin.modinfo modules.nsdeps \
1592	       compile_commands.json .thinlto-cache rust/test rust/doc \
1593	       rust-project.json .vmlinux.objs .vmlinux.export.c
1594
1595# Directories & files removed with 'make mrproper'
1596MRPROPER_FILES += include/config include/generated          \
1597		  arch/$(SRCARCH)/include/generated .objdiff \
1598		  debian snap tar-install \
1599		  .config .config.old .version \
1600		  Module.symvers \
1601		  certs/signing_key.pem \
1602		  certs/x509.genkey \
1603		  vmlinux-gdb.py \
1604		  *.spec rpmbuild \
1605		  rust/libmacros.so
1606
1607# clean - Delete most, but leave enough to build external modules
1608#
1609clean: rm-files := $(CLEAN_FILES)
1610
1611PHONY += archclean vmlinuxclean
1612
1613vmlinuxclean:
1614	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1615	$(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1616
1617clean: archclean vmlinuxclean resolve_btfids_clean
1618
1619# mrproper - Delete all generated files, including .config
1620#
1621mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1622mrproper-dirs      := $(addprefix _mrproper_,scripts)
1623
1624PHONY += $(mrproper-dirs) mrproper
1625$(mrproper-dirs):
1626	$(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1627
1628mrproper: clean $(mrproper-dirs)
1629	$(call cmd,rmfiles)
1630	@find . $(RCS_FIND_IGNORE) \
1631		\( -name '*.rmeta' \) \
1632		-type f -print | xargs rm -f
1633
1634# distclean
1635#
1636PHONY += distclean
1637
1638distclean: mrproper
1639	@find . $(RCS_FIND_IGNORE) \
1640		\( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1641		-o -name '*.bak' -o -name '#*#' -o -name '*%' \
1642		-o -name 'core' -o -name tags -o -name TAGS -o -name 'cscope*' \
1643		-o -name GPATH -o -name GRTAGS -o -name GSYMS -o -name GTAGS \) \
1644		-type f -print | xargs rm -f
1645
1646
1647# Packaging of the kernel to various formats
1648# ---------------------------------------------------------------------------
1649
1650%src-pkg: FORCE
1651	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1652%pkg: include/config/kernel.release FORCE
1653	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1654
1655# Brief documentation of the typical targets used
1656# ---------------------------------------------------------------------------
1657
1658boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1659boards := $(sort $(notdir $(boards)))
1660board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1661board-dirs := $(sort $(notdir $(board-dirs:/=)))
1662
1663PHONY += help
1664help:
1665	@echo  'Cleaning targets:'
1666	@echo  '  clean		  - Remove most generated files but keep the config and'
1667	@echo  '                    enough build support to build external modules'
1668	@echo  '  mrproper	  - Remove all generated files + config + various backup files'
1669	@echo  '  distclean	  - mrproper + remove editor backup and patch files'
1670	@echo  ''
1671	@echo  'Configuration targets:'
1672	@$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1673	@echo  ''
1674	@echo  'Other generic targets:'
1675	@echo  '  all		  - Build all targets marked with [*]'
1676	@echo  '* vmlinux	  - Build the bare kernel'
1677	@echo  '* modules	  - Build all modules'
1678	@echo  '  modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1679	@echo  '  dir/            - Build all files in dir and below'
1680	@echo  '  dir/file.[ois]  - Build specified target only'
1681	@echo  '  dir/file.ll     - Build the LLVM assembly file'
1682	@echo  '                    (requires compiler support for LLVM assembly generation)'
1683	@echo  '  dir/file.lst    - Build specified mixed source/assembly target only'
1684	@echo  '                    (requires a recent binutils and recent build (System.map))'
1685	@echo  '  dir/file.ko     - Build module including final link'
1686	@echo  '  modules_prepare - Set up for building external modules'
1687	@echo  '  tags/TAGS	  - Generate tags file for editors'
1688	@echo  '  cscope	  - Generate cscope index'
1689	@echo  '  gtags           - Generate GNU GLOBAL index'
1690	@echo  '  kernelrelease	  - Output the release version string (use with make -s)'
1691	@echo  '  kernelversion	  - Output the version stored in Makefile (use with make -s)'
1692	@echo  '  image_name	  - Output the image name (use with make -s)'
1693	@echo  '  headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1694	 echo  '                    (default: $(INSTALL_HDR_PATH))'; \
1695	 echo  ''
1696	@echo  'Static analysers:'
1697	@echo  '  checkstack      - Generate a list of stack hogs'
1698	@echo  '  versioncheck    - Sanity check on version.h usage'
1699	@echo  '  includecheck    - Check for duplicate included header files'
1700	@echo  '  export_report   - List the usages of all exported symbols'
1701	@echo  '  headerdep       - Detect inclusion cycles in headers'
1702	@echo  '  coccicheck      - Check with Coccinelle'
1703	@echo  '  clang-analyzer  - Check with clang static analyzer'
1704	@echo  '  clang-tidy      - Check with clang-tidy'
1705	@echo  ''
1706	@echo  'Tools:'
1707	@echo  '  nsdeps          - Generate missing symbol namespace dependencies'
1708	@echo  ''
1709	@echo  'Kernel selftest:'
1710	@echo  '  kselftest         - Build and run kernel selftest'
1711	@echo  '                      Build, install, and boot kernel before'
1712	@echo  '                      running kselftest on it'
1713	@echo  '                      Run as root for full coverage'
1714	@echo  '  kselftest-all     - Build kernel selftest'
1715	@echo  '  kselftest-install - Build and install kernel selftest'
1716	@echo  '  kselftest-clean   - Remove all generated kselftest files'
1717	@echo  '  kselftest-merge   - Merge all the config dependencies of'
1718	@echo  '		      kselftest to existing .config.'
1719	@echo  ''
1720	@echo  'Rust targets:'
1721	@echo  '  rustavailable   - Checks whether the Rust toolchain is'
1722	@echo  '		    available and, if not, explains why.'
1723	@echo  '  rustfmt	  - Reformat all the Rust code in the kernel'
1724	@echo  '  rustfmtcheck	  - Checks if all the Rust code in the kernel'
1725	@echo  '		    is formatted, printing a diff otherwise.'
1726	@echo  '  rustdoc	  - Generate Rust documentation'
1727	@echo  '		    (requires kernel .config)'
1728	@echo  '  rusttest        - Runs the Rust tests'
1729	@echo  '                    (requires kernel .config; downloads external repos)'
1730	@echo  '  rust-analyzer	  - Generate rust-project.json rust-analyzer support file'
1731	@echo  '		    (requires kernel .config)'
1732	@echo  '  dir/file.[os]   - Build specified target only'
1733	@echo  '  dir/file.rsi    - Build macro expanded source, similar to C preprocessing.'
1734	@echo  '                    Run with RUSTFMT=n to skip reformatting if needed.'
1735	@echo  '                    The output is not intended to be compilable.'
1736	@echo  '  dir/file.ll     - Build the LLVM assembly file'
1737	@echo  ''
1738	@$(if $(dtstree), \
1739		echo 'Devicetree:'; \
1740		echo '* dtbs             - Build device tree blobs for enabled boards'; \
1741		echo '  dtbs_install     - Install dtbs to $(INSTALL_DTBS_PATH)'; \
1742		echo '  dt_binding_check - Validate device tree binding documents'; \
1743		echo '  dtbs_check       - Validate device tree source files';\
1744		echo '')
1745
1746	@echo 'Userspace tools targets:'
1747	@echo '  use "make tools/help"'
1748	@echo '  or  "cd tools; make help"'
1749	@echo  ''
1750	@echo  'Kernel packaging:'
1751	@$(MAKE) -f $(srctree)/scripts/Makefile.package help
1752	@echo  ''
1753	@echo  'Documentation targets:'
1754	@$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1755	@echo  ''
1756	@echo  'Architecture specific targets ($(SRCARCH)):'
1757	@$(or $(archhelp),\
1758		echo '  No architecture specific help defined for $(SRCARCH)')
1759	@echo  ''
1760	@$(if $(boards), \
1761		$(foreach b, $(boards), \
1762		printf "  %-27s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1763		echo '')
1764	@$(if $(board-dirs), \
1765		$(foreach b, $(board-dirs), \
1766		printf "  %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1767		printf "  %-16s - Show all of the above\\n" help-boards; \
1768		echo '')
1769
1770	@echo  '  make V=n   [targets] 1: verbose build'
1771	@echo  '                       2: give reason for rebuild of target'
1772	@echo  '                       V=1 and V=2 can be combined with V=12'
1773	@echo  '  make O=dir [targets] Locate all output files in "dir", including .config'
1774	@echo  '  make C=1   [targets] Check re-compiled c source with $$CHECK'
1775	@echo  '                       (sparse by default)'
1776	@echo  '  make C=2   [targets] Force check of all c source with $$CHECK'
1777	@echo  '  make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1778	@echo  '  make W=n   [targets] Enable extra build checks, n=1,2,3 where'
1779	@echo  '		1: warnings which may be relevant and do not occur too often'
1780	@echo  '		2: warnings which occur quite often but may still be relevant'
1781	@echo  '		3: more obscure warnings, can most likely be ignored'
1782	@echo  '		e: warnings are being treated as errors'
1783	@echo  '		Multiple levels can be combined with W=12 or W=123'
1784	@$(if $(dtstree), \
1785		echo '  make CHECK_DTBS=1 [targets] Check all generated dtb files against schema'; \
1786		echo '         This can be applied both to "dtbs" and to individual "foo.dtb" targets' ; \
1787		)
1788	@echo  ''
1789	@echo  'Execute "make" or "make all" to build all targets marked with [*] '
1790	@echo  'For further info see the ./README file'
1791
1792
1793help-board-dirs := $(addprefix help-,$(board-dirs))
1794
1795help-boards: $(help-board-dirs)
1796
1797boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1798
1799$(help-board-dirs): help-%:
1800	@echo  'Architecture specific targets ($(SRCARCH) $*):'
1801	@$(if $(boards-per-dir), \
1802		$(foreach b, $(boards-per-dir), \
1803		printf "  %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1804		echo '')
1805
1806
1807# Documentation targets
1808# ---------------------------------------------------------------------------
1809DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1810	       linkcheckdocs dochelp refcheckdocs texinfodocs infodocs
1811PHONY += $(DOC_TARGETS)
1812$(DOC_TARGETS):
1813	$(Q)$(MAKE) $(build)=Documentation $@
1814
1815
1816# Rust targets
1817# ---------------------------------------------------------------------------
1818
1819# "Is Rust available?" target
1820PHONY += rustavailable
1821rustavailable:
1822	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh -v && echo "Rust is available!"
1823
1824# Documentation target
1825#
1826# Using the singular to avoid running afoul of `no-dot-config-targets`.
1827PHONY += rustdoc
1828rustdoc: prepare
1829	$(Q)$(MAKE) $(build)=rust $@
1830
1831# Testing target
1832PHONY += rusttest
1833rusttest: prepare
1834	$(Q)$(MAKE) $(build)=rust $@
1835
1836# Formatting targets
1837PHONY += rustfmt rustfmtcheck
1838
1839# We skip `rust/alloc` since we want to minimize the diff w.r.t. upstream.
1840#
1841# We match using absolute paths since `find` does not resolve them
1842# when matching, which is a problem when e.g. `srctree` is `..`.
1843# We `grep` afterwards in order to remove the directory entry itself.
1844rustfmt:
1845	$(Q)find $(abs_srctree) -type f -name '*.rs' \
1846		-o -path $(abs_srctree)/rust/alloc -prune \
1847		-o -path $(abs_objtree)/rust/test -prune \
1848		| grep -Fv $(abs_srctree)/rust/alloc \
1849		| grep -Fv $(abs_objtree)/rust/test \
1850		| grep -Fv generated \
1851		| xargs $(RUSTFMT) $(rustfmt_flags)
1852
1853rustfmtcheck: rustfmt_flags = --check
1854rustfmtcheck: rustfmt
1855
1856# IDE support targets
1857PHONY += rust-analyzer
1858rust-analyzer:
1859	$(Q)$(MAKE) $(build)=rust $@
1860
1861# Misc
1862# ---------------------------------------------------------------------------
1863
1864PHONY += misc-check
1865misc-check:
1866	$(Q)$(srctree)/scripts/misc-check
1867
1868all: misc-check
1869
1870PHONY += scripts_gdb
1871scripts_gdb: prepare0
1872	$(Q)$(MAKE) $(build)=scripts/gdb
1873	$(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
1874
1875ifdef CONFIG_GDB_SCRIPTS
1876all: scripts_gdb
1877endif
1878
1879else # KBUILD_EXTMOD
1880
1881filechk_kernel.release = echo $(KERNELRELEASE)
1882
1883###
1884# External module support.
1885# When building external modules the kernel used as basis is considered
1886# read-only, and no consistency checks are made and the make
1887# system is not used on the basis kernel. If updates are required
1888# in the basis kernel ordinary make commands (without M=...) must be used.
1889
1890# We are always building only modules.
1891KBUILD_BUILTIN :=
1892KBUILD_MODULES := 1
1893
1894build-dir := $(KBUILD_EXTMOD)
1895
1896compile_commands.json: $(extmod_prefix)compile_commands.json
1897PHONY += compile_commands.json
1898
1899clean-dirs := $(KBUILD_EXTMOD)
1900clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers $(KBUILD_EXTMOD)/modules.nsdeps \
1901	$(KBUILD_EXTMOD)/compile_commands.json $(KBUILD_EXTMOD)/.thinlto-cache
1902
1903PHONY += prepare
1904# now expand this into a simple variable to reduce the cost of shell evaluations
1905prepare: CC_VERSION_TEXT := $(CC_VERSION_TEXT)
1906prepare:
1907	@if [ "$(CC_VERSION_TEXT)" != "$(CONFIG_CC_VERSION_TEXT)" ]; then \
1908		echo >&2 "warning: the compiler differs from the one used to build the kernel"; \
1909		echo >&2 "  The kernel was built by: $(CONFIG_CC_VERSION_TEXT)"; \
1910		echo >&2 "  You are using:           $(CC_VERSION_TEXT)"; \
1911	fi
1912
1913PHONY += help
1914help:
1915	@echo  '  Building external modules.'
1916	@echo  '  Syntax: make -C path/to/kernel/src M=$$PWD target'
1917	@echo  ''
1918	@echo  '  modules         - default target, build the module(s)'
1919	@echo  '  modules_install - install the module'
1920	@echo  '  clean           - remove generated files in module directory only'
1921	@echo  ''
1922
1923endif # KBUILD_EXTMOD
1924
1925# ---------------------------------------------------------------------------
1926# Modules
1927
1928PHONY += modules modules_install modules_prepare
1929
1930ifdef CONFIG_MODULES
1931
1932$(MODORDER): $(build-dir)
1933	@:
1934
1935# KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules.
1936# This is solely useful to speed up test compiles.
1937modules: modpost
1938ifneq ($(KBUILD_MODPOST_NOFINAL),1)
1939	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
1940endif
1941
1942PHONY += modules_check
1943modules_check: $(MODORDER)
1944	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/modules-check.sh $<
1945
1946quiet_cmd_depmod = DEPMOD  $(MODLIB)
1947      cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
1948                   $(KERNELRELEASE)
1949
1950modules_install:
1951	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1952	$(call cmd,depmod)
1953
1954else # CONFIG_MODULES
1955
1956# Modules not configured
1957# ---------------------------------------------------------------------------
1958
1959modules modules_install:
1960	@echo >&2 '***'
1961	@echo >&2 '*** The present kernel configuration has modules disabled.'
1962	@echo >&2 '*** To use the module feature, please run "make menuconfig" etc.'
1963	@echo >&2 '*** to enable CONFIG_MODULES.'
1964	@echo >&2 '***'
1965	@exit 1
1966
1967KBUILD_MODULES :=
1968
1969endif # CONFIG_MODULES
1970
1971PHONY += modpost
1972modpost: $(if $(single-build),, $(if $(KBUILD_BUILTIN), vmlinux.o)) \
1973	 $(if $(KBUILD_MODULES), modules_check)
1974	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1975
1976# Single targets
1977# ---------------------------------------------------------------------------
1978# To build individual files in subdirectories, you can do like this:
1979#
1980#   make foo/bar/baz.s
1981#
1982# The supported suffixes for single-target are listed in 'single-targets'
1983#
1984# To build only under specific subdirectories, you can do like this:
1985#
1986#   make foo/bar/baz/
1987
1988ifdef single-build
1989
1990# .ko is special because modpost is needed
1991single-ko := $(sort $(filter %.ko, $(MAKECMDGOALS)))
1992single-no-ko := $(filter-out $(single-ko), $(MAKECMDGOALS)) \
1993		$(foreach x, o mod, $(patsubst %.ko, %.$x, $(single-ko)))
1994
1995$(single-ko): single_modules
1996	@:
1997$(single-no-ko): $(build-dir)
1998	@:
1999
2000# Remove MODORDER when done because it is not the real one.
2001PHONY += single_modules
2002single_modules: $(single-no-ko) modules_prepare
2003	$(Q){ $(foreach m, $(single-ko), echo $(extmod_prefix)$(m:%.ko=%.o);) } > $(MODORDER)
2004	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
2005ifneq ($(KBUILD_MODPOST_NOFINAL),1)
2006	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
2007endif
2008	$(Q)rm -f $(MODORDER)
2009
2010single-goals := $(addprefix $(build-dir)/, $(single-no-ko))
2011
2012KBUILD_MODULES := 1
2013
2014endif
2015
2016# Preset locale variables to speed up the build process. Limit locale
2017# tweaks to this spot to avoid wrong language settings when running
2018# make menuconfig etc.
2019# Error messages still appears in the original language
2020PHONY += $(build-dir)
2021$(build-dir): prepare
2022	$(Q)$(MAKE) $(build)=$@ need-builtin=1 need-modorder=1 $(single-goals)
2023
2024clean-dirs := $(addprefix _clean_, $(clean-dirs))
2025PHONY += $(clean-dirs) clean
2026$(clean-dirs):
2027	$(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
2028
2029clean: $(clean-dirs)
2030	$(call cmd,rmfiles)
2031	@find $(or $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
2032		\( -name '*.[aios]' -o -name '*.rsi' -o -name '*.ko' -o -name '.*.cmd' \
2033		-o -name '*.ko.*' \
2034		-o -name '*.dtb' -o -name '*.dtbo' \
2035		-o -name '*.dtb.S' -o -name '*.dtbo.S' \
2036		-o -name '*.dt.yaml' \
2037		-o -name '*.dwo' -o -name '*.lst' \
2038		-o -name '*.su' -o -name '*.mod' -o -name '*.usyms' \
2039		-o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
2040		-o -name '*.lex.c' -o -name '*.tab.[ch]' \
2041		-o -name '*.asn1.[ch]' \
2042		-o -name '*.symtypes' -o -name 'modules.order' \
2043		-o -name '*.c.[012]*.*' \
2044		-o -name '*.ll' \
2045		-o -name '*.gcno' \
2046		-o -name '*.*.symversions' \) -type f -print \
2047		-o -name '.tmp_*' -print \
2048		| xargs rm -rf
2049
2050# Generate tags for editors
2051# ---------------------------------------------------------------------------
2052quiet_cmd_tags = GEN     $@
2053      cmd_tags = $(BASH) $(srctree)/scripts/tags.sh $@
2054
2055tags TAGS cscope gtags: FORCE
2056	$(call cmd,tags)
2057
2058# Script to generate missing namespace dependencies
2059# ---------------------------------------------------------------------------
2060
2061PHONY += nsdeps
2062nsdeps: export KBUILD_NSDEPS=1
2063nsdeps: modules
2064	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/nsdeps
2065
2066# Clang Tooling
2067# ---------------------------------------------------------------------------
2068
2069quiet_cmd_gen_compile_commands = GEN     $@
2070      cmd_gen_compile_commands = $(PYTHON3) $< -a $(AR) -o $@ $(filter-out $<, $(real-prereqs))
2071
2072$(extmod_prefix)compile_commands.json: scripts/clang-tools/gen_compile_commands.py \
2073	$(if $(KBUILD_EXTMOD),, vmlinux.a $(KBUILD_VMLINUX_LIBS)) \
2074	$(if $(CONFIG_MODULES), $(MODORDER)) FORCE
2075	$(call if_changed,gen_compile_commands)
2076
2077targets += $(extmod_prefix)compile_commands.json
2078
2079PHONY += clang-tidy clang-analyzer
2080
2081ifdef CONFIG_CC_IS_CLANG
2082quiet_cmd_clang_tools = CHECK   $<
2083      cmd_clang_tools = $(PYTHON3) $(srctree)/scripts/clang-tools/run-clang-tools.py $@ $<
2084
2085clang-tidy clang-analyzer: $(extmod_prefix)compile_commands.json
2086	$(call cmd,clang_tools)
2087else
2088clang-tidy clang-analyzer:
2089	@echo "$@ requires CC=clang" >&2
2090	@false
2091endif
2092
2093# Scripts to check various things for consistency
2094# ---------------------------------------------------------------------------
2095
2096PHONY += includecheck versioncheck coccicheck export_report
2097
2098includecheck:
2099	find $(srctree)/* $(RCS_FIND_IGNORE) \
2100		-name '*.[hcS]' -type f -print | sort \
2101		| xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
2102
2103versioncheck:
2104	find $(srctree)/* $(RCS_FIND_IGNORE) \
2105		-name '*.[hcS]' -type f -print | sort \
2106		| xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
2107
2108coccicheck:
2109	$(Q)$(BASH) $(srctree)/scripts/$@
2110
2111export_report:
2112	$(PERL) $(srctree)/scripts/export_report.pl
2113
2114PHONY += checkstack kernelrelease kernelversion image_name
2115
2116# UML needs a little special treatment here.  It wants to use the host
2117# toolchain, so needs $(SUBARCH) passed to checkstack.pl.  Everyone
2118# else wants $(ARCH), including people doing cross-builds, which means
2119# that $(SUBARCH) doesn't work here.
2120ifeq ($(ARCH), um)
2121CHECKSTACK_ARCH := $(SUBARCH)
2122else
2123CHECKSTACK_ARCH := $(ARCH)
2124endif
2125checkstack:
2126	$(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
2127	$(PERL) $(srctree)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
2128
2129kernelrelease:
2130	@$(filechk_kernel.release)
2131
2132kernelversion:
2133	@echo $(KERNELVERSION)
2134
2135image_name:
2136	@echo $(KBUILD_IMAGE)
2137
2138quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN   $(wildcard $(rm-files)))
2139      cmd_rmfiles = rm -rf $(rm-files)
2140
2141# read saved command lines for existing targets
2142existing-targets := $(wildcard $(sort $(targets)))
2143
2144-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
2145
2146endif # config-build
2147endif # mixed-build
2148endif # need-sub-make
2149
2150PHONY += FORCE
2151FORCE:
2152
2153# Declare the contents of the PHONY variable as phony.  We keep that
2154# information in a variable so we can use it in if_changed and friends.
2155.PHONY: $(PHONY)
2156